1. Field of the Invention
The present invention relates generally to devices for use in medical procedures, and more particularly, relates to guide wires for directing a catheter or other medical device through the cardiovascular system or other passage way in the human body.
2. Description of the Prior Art
Guide wires for positioning various medical devices within the body have been known for some time. A common current application for guide wire is in percutaneous translumenal coronary angioplasty (PTCA). In this procedure, it is often necessary to steer a guide wire from an entry point in the arterial system, such as the femoral artery, to the site of occlusion of a coronary artery. A dilatation catheter can then be easily advanced over the guide wire to the treatment site.
In PTCA applications, it is necessary that the guide wire have a small diameter, be flexible enough to negotiate the tortuous arterial pathways without danger of perforation, and have sufficient steerability to permit the attending physician to select the desired pathway from a number of alternatives as branches in the arterial system are encountered. The ideal guide wire must have a flexible and bendable tip, along with the ability to evenly transmit torque from the proximal end to the distal end.
U.S. Pat. No. 4,545,390, issued to Leary shows a typical design of a guide wire for PTCA applications. In the Leary guide wire, the central core wire terminates short of the distal tip. The result is that the guide wire will tend to bow at the distal tip upon application of longitudinal force. U.S. Pat. No. 4,763,647, issued to Gambale, shows a similar design with an even shorter central core wire.